Verified on CFME-5.7.0.9, and RHV-4.0.4 "Validation" button grayed out, till Database Name Field was filled.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://rhn.redhat.com/errata/RHBA-2017-0012.html